The majority of the processes used in the treatment of fibrous materials, such as textiles and paper, entail immersion of the material in an aqueous bath containing the treating compound. Consequently, the equipment used in such processes includes facilities for the applying the aqueous compositions followed by means for removing the excess water from the treated substrate, such as squeeze rolls, extractors and driers. More recently, processes for applying the treating compositions in the form of a foam have been developed; however, the equipment or apparatus uses to apply the foam leaves much to be desired, as can be seen from the descriptions of U.S. Pat. No. 1,948,568, U.S. Pat. No. 3,697,314 and U.S. Pat. No. 3,762,860. The equipment disclosed in these references requires suspension of the textile in the foam bath, conveying the textile or yarn through the foam, or padding the textile with the foam followed by heating to break the foam.